UX: Update Thinker module pages with user-friendly text

- Prompts: Changed 'AI Prompts Management' to 'Prompt Library'
- Author Profiles: Changed to 'Writing Styles'
- Strategies: Changed 'Content Strategies' to 'Content Plans'
- Image Testing: Changed to 'Image Settings'
- Dashboard: Changed 'Thinker Dashboard' to 'Strategy Dashboard'

frontend/src/pages/Thinker/Dashboard.tsx

@@ -146,8 +146,8 @@ export default function ThinkerDashboard() {
 
   return (
     <>
-      <PageMeta title="Thinker Dashboard - IGNY8" description="Strategic OS and thinking engine" />
-      <PageHeader title="Thinker Dashboard" />
+      <PageMeta title="Strategy Dashboard - IGNY8" description="Manage your content strategy" />
+      <PageHeader title="Strategy Dashboard" />
 
       <div className="space-y-6">
         {/* Key Metrics */}